Mobile telecommunications systems are known. One such example is the public land line mobile network (PLMN), of which cellular communications networks are an example. Another example is a mobile communication system that is based, at least partially, on use of communication satellites.
As the penetration rate of mobile phones into the population has increased, the incidence of theft, with or without violence, of such devices has increased. Whilst theft of current generation devices is costly and inconvenient to owners, the increase in available services and associated costs as networks are developed into the next generation mean that the potential for losses to users, network and insurers is higher than is presently the case. This is particularly the case where mobile devices are able to access high cost services, or even capable of transferring cash value between bank accounts or various credit- or debit-based accounting systems.
One way to improve the security of mobile devices is to increase the amount of effort needed by the user to access services on the device. Many mobile handsets presently available, for example, can be configured to require a password to be input each time the device is to be used. Whilst this effectively prevents the device being used if it is stolen, entering, say, a personal identification number (PIN) or password each time a call is to be made is tedious for the user. In many cases, the user can disable this feature if it is known the phone is to be in safe environment, such as the user's home. However, changing the security status each time the user moves from a safe to an unsafe environment is also tedious. Moreover, if the user forgets to turn the security on, or if the device is stolen from the safe environment with the security disabled, there is nothing to stop the thief from accessing the services available via the phone.
In an unrelated aspect of mobile telecommunications, information regarding the geographical location of mobile devices can be ascertained for various purposes, such as accessing location-based services. For example, fairly accurate geographical location information can be obtained based on satellite-based GPS (Global Positioning System). More accurate location information can be obtained through differential GPS techniques.
Another possibility is to use a location service based on a cellular telecommunications system. In this approach, the cells or similar geographically limited radio access entities and associated controllers of the communication system are utilised in production of at least a rough estimate of the current location of the mobile user equipment. To improve the accuracy of the location information the communication system may be provided with specific location measurement units that provide more accurate data concerning the location of user equipment within the service area of the cellular system.
It is also possible to ascertain a geographical location when the mobile user equipment is located within the coverage area of a visited or “foreign” network. The visited network may be made capable of transmitting the location of the mobile user equipment back to the home network, e.g. to support services that are based on location information or for the purposes of routing and charging.
The location data may be processed in a specific location service entity that is implemented either within the cellular system or connected thereto. The location data may also be processed in the user equipment that is provided with appropriate processing capacity. The location service entity provided by the communication system may serve different clients via an appropriate interface.
The location information may be used for various purposes, such as for location of a mobile telephone that has made an emergency call, for locating vehicles or given mobile subscribers and so on.
An example of the provision of the location information by a PLMN is described in more detail 3rd Generation Partnership Project (3GPP) technical specifications, see e.g. 3GPP TS 23.271 version 4.2.0, titled “Functional stage 2 description of LCS”, June 2001.
It is an object of the present invention to improve the ease with which multiple levels of security can be implemented in a mobile device configured for use within a communications network.